A Closer Look at What Drives Health Disparities

November 14, 2013

One particularly vexing problem confronting public health officials and researchers is the persistence of racial and ethnic disparities in health and health care. New research by Kim Rhoads, MD, MS, MPH, a Robert Wood Johnson Foundation (RWJF) Harold Amos Medical Faculty Development Program scholar (2009-2013) and a colorectal surgeon at Stanford University School of Medicine and Cancer Institute, offers important insights.

Rhoads and her team at Stanford examined data on patients with colorectal cancer, an area in which a race- and ethnicity-based mortality gap has been widening. Their research focused on where patients received their care and, specifically, which patients were treated at cancer centers recognized by the National Cancer Institute (NCI) for providing high-quality care and producing better cancer outcomes.

Some 67 such facilities are spread across the nation, including nine in the researchers' home state of California. Using California-specific databases that included demographic, clinical, and socio-economic status information, Rhoads and colleagues applied statistical analysis to the records of more than 79,000 patients with colorectal cancer, seeking to identify the factors that most significantly affected where they were treated.

They found that geography plays a central role in the decision about where treatment is delivered, with the data corroborating earlier published studies suggesting that patients much prefer to be treated in facilities near their homes. The median travel distance between colorectal cancer patients' homes and their treatment locations was less than five miles.

Significantly, a larger proportion of minorities lived less than five miles from an NCI-designated facility than non-minorities. However, of those living nearby, fewer minorities used these facilities for cancer treatment than non-minority patients. The difference did not appear to be explained by insurance status. Instead, as Rhoads points out, cultural factors and patient preference also play a huge role in determining where cancer is treated. "Some patients, particularly those in minority groups, have clustered for care in specific hospitals, perhaps where they feel most comfortable; and those trends have persisted over time. So if the local hospital where you or a family member has been treated for any other medical condition is not an NCI-designated cancer center, chances are that’s still where you’re going to go for cancer care."

Moreover, Rhoads observes that "provider networks and affiliations have historically been segregated, and providers who serve low-income and minority populations have reported significant challenges in getting their patients referred to high-quality settings for care." Rhoads explains that this may also negatively affect a minority patient’s ability to obtain treatment in an NCI setting.

Education, Unemployment, Poverty

Rhoads and her team also investigated socio-economic status factors and their impact on location of care. Using census data, they analyzed neighborhood unemployment, levels of education, and the percentage of families with incomes less than 200 percent of the federal poverty level. They found that both high unemployment and high poverty were associated with low utilization of NCI centers, but that a high neighborhood education level was an even stronger predictor of high utilization. The authors conclude: "Patients living in neighborhoods dense with college graduates have higher odds of using NCI cancer centers. These findings suggest the importance of education, independent of neighborhood-level poverty and unemployment or travel distance."

Rhoads explains, "Education dictates a lot of how you interface with the world and how the world interfaces with you. … Patients with lower levels of education might be more inclined to rely on shared experiences of family, friends, and neighbors, rather than on published data about hospital quality.” But it's not all about patients choosing to go with familiar facilities instead of unfamiliar ones with better track records. "There’s also a way in which patients considered to be less well-educated may not be offered all of the potential options. It’s a very paternalistic, non-patient-centered approach," she says. “In some cases, providers essentially make choices for patients based on what they think the patient can handle or understand.”

Partnerships Between NCI-Designated Settings and Community Facilities

The findings hold lessons that extend beyond colorectal cancer. As Rhoads says, "The disease is a perfect model for examining quality of cancer care because there's a very organized pathway that leads from pre-cancerous lesions or polyps to the formation of cancer, and we have a pretty good handle on that. So with appropriate primary care that includes screening and early detection, colorectal cancer is largely preventable and eminently survivable. A similar approach to the management of other cancers may directly address survival disparities.”

From a policy perspective, Rhoads suggests that changes in the NCI's standards for certification could help improve treatment for minority patients. "NCI is really pressing institutions to do cancer prevention and control work in their surrounding communities," she says, "and I would argue that the work should be expanded to encourage institutional partnerships” where NCI-designated centers share resources with community hospitalsat which minority and low-income populations receive care. Successful partnerships, she adds, “would increase community hospitals’ adherence to evidence-based treatment guidelines and to offer technical support for more complicated cases.” Over the long run, Rhoads believes that these partnerships are critical, adding, “If we fail at sharing resources, disparities in access to high quality equitable care and best outcomes will persist and continue to worsen.”

Rhoads' study, conducted with her research team of Lyen C. Huang, MD, MPH; Yifei Ma, MS; and Justine V. Ngo, MHA, is published in the October issue of Cancer.